Research On The Curing Technique Of UVCC-IM-1 Coating On PC Film

Polychlorinated p-xylene membrane(hereinafter referred to PC film) is widely used in many fields, such as electronic devices,semiconductor, sensors and materials protection industries, because of its excellent physical and mechanical properties, low humidity permeation, electrical insulation, anti-corrosion, etc. Nevertheless, the adhesive strength between PC film with other materials is low due to its low surface energy. Meanwhile, the brittleness of the PC film will be high and the impact strength becomes worse with increase of its thickness. It is a common method to improve the impact resistance of the coating and increase the bonding force between PC film with base substrate by coating organic film on the surface of PC film. The traditional surface coating of PC film is phenolic varnish. However, the preparation of phenolic varnish is limited for its complex process and long curing time. Our team developed a substitutional method for PC membrane surface modification by using ultraviolet curing technology,and obtained the main contents of the UV curing paint(code named UVCC-IM-1). The results show that the adhesion strength and the impact resistance of PC film after coated with UVCC-IM-1 are greatly improved. However, there is lack of research on the curing process parameters of UVCC-IM-1 film and the influence of impurities in paint or environmental temperature and humidity on the curing properties.In this study, the influence of the related factors on the curing properties of the paint was studied on the basis of the existing paint formulation in order to obtain optimized curing process parameters of UVCC-IM-1 film. And the effects of curing conditions on the properties of PC film and PC-paint composite film were also evaluated. The resultcan provide technical support for the construction process of the curing paint on the surface of PC film. The main results are list as follows:Trace amount of water in UVCC-IM-1 paint has a certain effect on the curing of the film, which needs to be removed before curing. The remainder ethyl acetate, as diluent in paint, has a significant effect on the curing of the film, and needs to be removed completely. For the film with thickness of 50 μm, the solvent can be evaporated completely when the paint film is heated at 80 ℃ for 6~8 min or naturally volatilized at room temperature for about 3 h. The environmental temperature has no obvious effect on the curing properties of UVCC-IM-1 film, but the excess environmental humidity will affect the curing of paint film.Based on the studies of the relationships of the curing properties with such factors as ultraviolet optical density, film thickness and curing time, the optimized process parameters for curing the UVCC-IM-1 film on the surface of PC film are obtained. The proper optical density for UVCC-IM-1 paint film cured on surface of PC film is approximately 8.2 m W/cm2 with the wavelength of 365 nm. Under such optical density, the film curing time(y/s) and thickness(x/μm) has a linear relationship of y=0.117x-0.41 at the thickness range of 10~70μm.The curing time is only 5 s for the UVCC-IM-1 film with thickness of 50 μm on the surface of PC film under the light intensity of 8.2m W/cm2. Such curing parameters does not affect the microstructure and properties of PC film. The temperature(80 ℃) and time(less than 10min) for the diluent volatilizing has also no influence on the structures and properties of PC film or PC-paint composite film.The adhesion strength between PC film and UVCC-IM-1 filmprepared at the optimized curing parameters reaches 1.3 MPa. And the solvent resistance of curing film is better than that of traditional phenolic paint in some commonly used solvents such as xylene and petroleum ether.